Defense Grid: The Awakening [(Intel) Article]

The enigmatic computer called Entity needs your help: build various types of towers — from basic gun turrets to lightning-dealing teslas — to stop the alien hordes threatening to overrun a desolate planet. The invaders come in 15 varieties, however, so you’ll need to plan your strategy carefully or they’ll escape with the power cores needed to turn on a dormant defense grid. “Be merciless. They are,” Entity advises.

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Good game for timekilling))